Consumable liquid food products are often sold in packages made of sterilized packaging material. Typical examples for such packages include the Tetra Brik® Aseptic in the shape of a brick stone.
The packaging material used for those packages comprises a multilayer structure. One or more layers of plastics, and aluminum foil (depending on the package type) are laminated on both sides of a card board of paperboard layer, the latter having different stiffness, strength and thicknesses depending on the package type.
Packages of this sort are normally produced on fully automatic packaging machines, on which a continuous tube is formed from the web-fed packaging material; the packaging material is sterilized inside the packaging machine, e.g. by radiating the web using a low voltage electron beam or a chemical sterilization agent. The material is then folded in a sterile environment and sealed longitudinally to form a vertical tube.
The tube is filled with the sterilized or sterile-processed food product, is sealed transversally and subsequently cut along equally spaced cross sections to form parallelepiped-shaped packages like the above mentioned package.
To open the packages described above, various solutions have been proposed. In patent application WO2009000927, by the present applicant, an alternative opening device is presented. In that application a spout and a corresponding membrane is injection molded in the same molding step, directly onto a sheet of packaging material.
Despite the variances of opening for the different packages, there is still a need for further variances, particularly for high pouring speed, but also with reduced material consumption and production time.